Electrical gas-lamp.



F. SKAUPY.

ELECTRICAL GAS LAMP.

APPLICATION FILED SEPT. I 1. 1913.

WE L

T .d k 5 Patented Apr. 11,1916.

v INVENTOR FRANZ am UPV A TTORIVE Y8 mmsmun, or BERLIN, ermmanx, ASSIG-NOB. 'ro DEUTSCHE us mmm 4 AKTIENGESELL'SCHAFT (nonnonsnmscanr'r), or BERLIN, GERMANY, 5 con 2031121011 or GERMANY;

7 '0 all whom it may concern: I

Be it known that I, FRANZ SKAUPY, subject of the Emperor of Austria-Hungary,

and a resident of Berlin, Germany, have 1nvented a new and useful Improvement in Electrical Gas-Lamps, of which the following is a specification.

. My invention relates to a lamp in which illumination is produced by the action of electrical currents upon a rare gas or gases.

My invention relates particularly to an improvement in the type of electrical gas lamp described in my pending United States application having the same title as this case Serial Number 7 53,692 filed March '12, 1913, in which type of lamp a sealed bulb is filledwith a suitable rare gas at a low pressure, preferably about 1' mm. while the cathode is constituted of an electro positive material of low density such, e. g., as sodium, potassium, or an -alloy of such metals. In such lamps the electrical conduction therethrough, by means of which illumination is produced, is of arc-like character as distinguished from a glow discharge; the illumination. is furnished altogether by the gas and in no wise by the cathode material. The

bulbs of such lamps may be considered as comprising two portions, viz: a light tube or space containing the rare gas and becoming luminous when the lamp is operated, and'a cathode receptacle or space which holds the metal or alloy forming the cathode as aforesaid.

The particular object of the present invention is in the type of lamp referred to, to more effectively fprevent particles of the In my prior application referred to I have disclosed a means for preventing these particles from entering the Y lighttube, but such means is not necessarily effective to prevent some small portion of said particles from'passmg over since the dimensions of the means selected may not be chosen exactly right and other accidental causes may intervene.

It has been found that the bulk of the cathode particles (for example sodium) which pass into the light tube by reason of 'insuflicient protection of the cathode, are

produced by Spurting from the continually shifting light point on the cathode. To prevent this spurted and vaporized material om passing over, into the Elmore Icarens-LAMP.

Specification of Letters Patent.

fore necessary to arrange matters as far as' Patented Apr. 11, 1916. Application filed September 11, 1913. erial No. 789,308. 7 I I possible so that there shall be no straight line of travel from the glowing l-i ht polnt into the llght tube, since, as is we'l known, 7

such spurtings only take place along straight" lines.

In the present invention the difiicultylspecified is avoided by employing a tube like connectionbetween the light tube and the cathode receptacle, or space which connection is substantially smaller in cross-section than said receptacle.

y invention will be better understood by I referring to the drawings in which .Figure 1 representsa diagrammatic sectional view of a preferred'embodiment: Fig. 2 represents a similar view of a modification; Fig. 3 represents a similar view of a thirdoform of my invention and Fig. 4 represents still another form of my invention.

Referring to the drawings a is the light tube or space, I! the cathode and c the cathode receptacle. The connection tube d (1n Fig. 1,) of cross-section relatively much smaller than that of the light tube proper is provided with a flange e by which the former is fixed concentrically to the inner. wall of, I

the light tube a. The tube d extends very nearly to the surface of the cathode metal.

In the modification of Fig.2 the connecting tubed forms part of a separate insert 9 arranged to fit snugly within the light tube a which latter is provided with a circumferentia'l indentation or collar 7 upon which the insert rests, lower than which said insert cannot pass.

In Figs. 3 and 4 the connecting tube at is combined with an independent receptacle :or insert g which prevent access of the light point to the glass wall of the light tube. I find this to be a very convenient form of the invention.

In the form shown in Fig. 3 the upper part of the insert is flanged over centrally and then downwardly to constitute the connecting tube (1., In the modification of Fig. 4, the tube 03 is formed at the top of the pearshaped insert 9 placed in the bottom of the light tube.., I

As is well known, in lamps of this type, the light point or active point of, the cathode, i. e., the point uponthe cathode at which the electrical arc-like discharges are is continually moving irregularly concentrated, is always at the edge of the cathode material where its upper surface contacts with the cathode receptacle. During the operation of the lamp the li 'ht point 'om one spot to another around this edge.

In none of the modifications of the invention shown is there a straight line pas- 'sage from the edge of the cathode metal to the interior of the light tube.

It is not necessary, to obtain the advantages of my invention, that every straight line passage from the light point to the interior of the light tube be cut 0d the advantages will be obtained in part if the possible straight line passages are out ofi' in part.

I find that in all of these lamps equipped with any form of my present inventlon the light point or light are is much more quiet than when the device of the invention is omitted and shows a much smaller tendency to climb up the walls of the cathode holder. I find that the lamp of Fig. 3, which employs an independent combined insert and connecting tube, permits the particles of\ cathode material readily to flow back upon the cathode and I also find as .a result of experience that in this form of lamp the insert a may be madeof ve v small dimensions.

maaeea on the line of intersection of the free cathode surface with the wall of the receptacle.

sealed tube having a light space filled with a rare gas, and a cathode receptacle containing a suitable cathode material, said space and said receptacle being separated by a wall formed with a perforated extension said extension being so dimensioned that its material will be intersected by. all straight lineswhich may be drawn between any point on the wall of the light space and any oint on the line of intersection of the free cathode surface with the wall of the receptacle. Y 3. An electrical gas lamp comprising a sealed tube the one part of which constitutes a light space, and an independent cathode receptacle in the other part of said tube said receptacle containing a suitable cathode ma- 2. An electrical gas lamp comprising a terial, the part of said receptacle adjacent to the light space being turned inwardly and away from the light space so as to form a'tube which ends near the cathode material and the wall of said tube being so di- A mensioned that its material will be intersected by all straight lines which may be drawn between any point on the wall of the light space and any point on the line of intersection of the free cathode surface with i the wall of the receptacle.

In testimony whereof I have hereunto set my hand in the presence of two subscribing FRANZ SY.

"witnesses.

Witnesses:

IWOLDEMAR HAUPT,

HARRY L. WILSON. i 

